Readme references non-existant stagehand.config.ts file

[theoephraim]

The readme in the generated app mentions updating a stagehand.config.ts file which does not exist in the template.

To run on a local browser, add your API keys to .env and change env: "LOCAL" to env: "BROWSERBASE" in stagehand.config.ts.

This appears to be set within the index.ts file itself.